Magnetic firing mechanism for submarine mines



H. MAXIM.

MAGNETIC FIRING MECHANISM FOR SUBMARINF. MINES.

APPLICATION FILED 050.1, 1911.

1,389,566, Patented Aug- 30, 1921.

3 SHEETSSHEET l- -V// 4 H5) amawtoz H. MAXIM. MAGNETIC FIRINGMECHANISM FOR SUBMARINE MINES} APPFICATION FILED DEC-7| 9l7.

Patented MS- 30, 1921.

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MAGNETIC FIRING MECHANISM FOR SUBMARINE MINES.

APPLICATION men DECJ, 1911.

1 3 9 5 I Patented Aug. 30, 1921.

3 SHEET$SHEET 3.

5 wue W601 UNITED ST TES PATENT OFFICE.

HUDSON.MAX1M, or. HOPATCONG- BOROUGH, NEW JERSEY.

MAGNETIC FIRING MECHANISM FOR SUBMARINE MIN 'E S.

Specification of Letters Patent. Patented A g; 30 1921 Application filed December 7, 1917. Serial no.2o5,9i7. 1

Landing, New Jersey, have invented certain new and useful Improvements in Magnetic Firing Mechanism forSubmarine Mines, of which the following is a specification.

The present inventionrelates to a firing mechanism for exploding submarine mines without contact between the mine and the vessel to be destroyed.

Its object is mainly to provide a magnetic firing mechanism whose normal stability will be so far disturbed or influenced by the near approach of a comparatively large mass of steel, such as the hull of avessel, as to cause the mechanismvtofunction by closing an electric circuit, thereby exploding a detonator and firing the mine.

In carrying out the invention two or mor magnetic needles or magnetic rods are sov arranged with respect to each other or one another that upon the approach of-a steel vessel all of the needles are caused to be moved under the magnetic'infiuence.

One of the needles will be caused to move more quickly-than the other needle or needles utilized directly to fire the detonator and eX-' plode the mine or indirectly tocause another magnetic needle to be rotated upon its axis until it is arrested by an electric contact point, thereby establishing an independent electric circuit through the detonator to explode the mine, the firing needle in which case is preferably held in a fixed position by a permanent magnet while an electromagnet stronger than the permanent magnet, when energized by the establishment of the first-named electric current, will serve to turn the firing needle around until it strikes the electric contact point to explode the mine. l 1 4 This firing needle ispreferably arranged on a horizontal axis with the permanent and electro-magnets and the needle in axial alinement' with the axis of the other magnetic needles. The, firing needle may be made to rotate with any degreeof slowness so that in the event of an electric'current being established in the electro-magnet from the fluctuation of the needle establishing a current due to the surging of the sea, a suflicient'time will elapse to allow the contact to be broken.

. -Any momentary flickering or oscillation of'the first-named needle or needles establish- 'ing the first-named circuit'will not have sufficient duration of rest in its operable or circuit making position tohave swung the firmg needle around to its firing position. Consequently, the mine can be fired only by the near approach of a large steel mass, such as the hull of a vessel, and the duration of whlch near position will necessarily on all occasions be sufiicient to allow the slow-movmg firing needle t0 be swung around into firing position.

Theimproved mechanism is shown "in the accompanying drawings, in which, a

F igures 1 and 2, are vertical sectional elevations taken at right angles one to the other.

8, is a plan view thereof. i

Fig. 4, is an enlargedsectional elevation of the mechanism removed from its case and with some of its parts omitted.

Fig. 5, is a plan View of one of the magnetic needles.

F ig. 6, is a sectional view of a submarine mine provided with the invention.

Fig. 7, is an enlarged sectional elevation of the firing needle and its casing.

The improvement is preferably contained 7 in two casings A and B, in Fig. 6, separated -a distance apart and as shown, separated nearly as wide as the diameter of the mine C, will allow.

The submarine mine with which the improvement is associated may be of any of the usual forms. That shown in Fig. 6, consists of a hollow spherical shell C, which may be :in two halves, the abutting flanges of the The hemispheres being bolted together. lower half, containing the casing B, and filled with the high explosive charge, is separated from the upper half, containing the casing A and the necessary electric batteries, by a central partition H, at the equator[ The casing A, Figs. 1, 2 and 3, containing the sensitive magnetic needle and its appurtenances, consists of a cylindrical'shell 10, with base 11 and cap 12, made of nonwater-tight. The casing B, containing the firing magnetic needle and its appurtenances, likewise consists of a shell 13, with base and cap pieces.

The casing A contains a rectangular open magnetic material, such as brass, and made frame 14, of brass, confined in place by vertical guides 15, formed on the shell 10, which permit the vertical removal bodily of the entire magnetic mechanism.

The frame 14 supports a centrally located vertical pivot or axial rod 16, of aluminum, forming a carrier for a compound magnetic needle consisting, in this instance, of three needles, a, b, 0.

In the construction shown, the lower magnetic needle a, is preferably the larger and longer needle, and consequently the slowermoving needle, and in its normal position constantly points north and south; the upper needle 0, being smaller and shorter, and hereinafter" termed the sensitive needle, will under the influence. of the larger needle stand at right angles thereto and point, substantially, east and west. In a properly balanced mechanism, both mechanically and magnetically, the still smaller intermediate or control needle I), need not be employed, but to obtain the proper adjustment, in practice, of the sensitive needle 0, with respect to the needle 0;, the correcting or controlling needle I), is preferably used. The needle I), is ad justable on the rod 16, with respectto the needles a and 0, so that its ultimate and effective position with respect thereto may be secured.

In operation, when a large mass of steel, such as a vessel, is sufficiently near as to disturb the stability of the magnetic needles, the sensitive needle 0, being smaller and lighter than the needle a, is deflected more quickly than the larger needle a, with the result that an electric circuit is closed, eventu ating in the firing of the mine.

The pivot-rod 16, carrying the magnetic needles, is sensitively mounted between two centers, 17, 18, carried by the top and bottom horizontal members of the frame 14.-

Each of these centers, see Fig. 4, consists of a screw 9, say of manganese steel, with a reduced conical end forming the center, that bears on a jewel 8, supported by a coiled spring 7, both mounted in a cavity or countersink 6, in the end of the rod 16. The jewel 8, is a small, thin disk of high-grade steel, glass hardened. The center-forming portion of the screws 9, project into the cavities 6, a sufficient distance to prevent accidental dislodgment of the pivot-rod with respect to its centers.

For the purpose of the electric circuit to be hereinafter described, the pivot-rod 16 is made in two portions, an upper and a lower portion, rigidly united by a rod or sleeve 19, of hard rubber or other insulating material. The upper portion of the pivot-rod is formed into a yoke 31, to provide space for the amount and movement of the upper or sensiti ve magnetic needle 0. This needle-is carried by a supplemental plvot oraxlal-rod 20, of aluminum, carrying at its ends centers 21, bearing like the others described, against steel jewels 5, supported by coiled springs 4, in cavities, in the axis of the yoke.

Each of the magnetic needles a, b, and c, are of similar construction and mounting. Thus the needle 0, Fig. 5, consists of a pair of steel rods cl, carried by a hub e, of alumi num, which in turn has a central hole to slip on to its pivot-rod 20, and be there secured in proper vertical position and arrangement by a pair of set-screws f. The needles are each of a size and length suited to its particular duty in the mechanism.

The entire magnetic mechanism may be wholly immersed in a liquid, such as kerosene oil, filling the casing A, to damp the movements of the magnetic needles. To render the slow-moving magnetic needle a, still more sluggish, the pivot-rod 16, may carry a set of broad-faced vanes 22; and likewise to lessen the flickering of the sensitive needle 0, its pivot-rod 20, may carry a set of narrow-faced vanes 23.

Taking advantage of the immersion of the mechanism in a body of liquid, the pivot-rod 16, may carry a suitable float 24, formed by a hollow body of light material, such as aluminum, or a cork body, thus to compensate for the weight of the mechanism and remove the load from the lower center 18. So, too, the sensitive needle pivot-rod 20, may carry a suitable float 25, to remove the weight from its lower center 21.

The frame 14 may carry a crosswise partition 50, to divide the liquid and thus prevent surging. This partition is divided centrally into two halves, each supported by lugs 51, on the vertical members of the frame 14, resting also on other lugs 52, on the shell 10.

The lower portion of the pivot-rod 16 and its center 18, which is directly carried by an insulating bushing 26 in the frame 14, forms part of an electric circuit including a pair of Wires 2, carried for convenience of construction by a collar 27, on a reduced por tion of the pivot-rod 16, immediately below the insulating sleeve 19; which wires 2, extend upward through guide eyes formed with said sleeve, with their ends bent into a loop form to straddle and be directly in the path of other wires 3. extending horizontally directly from the supplemental pivot-rod 20, Figs. 1 to 4. The circuit thence continues through the pivot-rod 20, upper centers 21 and 17, to the frame 14. The circuit outside the casing A,'is continued by a binding post 28, fast to the base 11, and in metallic contact with the frame 14, and by another bindingpost 29, carried by an insulating bushing 30, in said base, with the metallic end of this latter binding post in contact with the lower center 18, which is insulated from the frame 14, as before described. The exterior portion of the circuit may then be continued by wires leading from the two binding posts 28,29, to include a depth circuit-maker D, an electric battery E, and a detonator F.

The ends of the wires 2, are looped or bent as shown to meet and contact with the wires 3, in either direction to the left or to the right that the needle 0', may be deflected. These wires 2 and 3 are duplicated simply to preserve the perfect balance of the mecha nism; and the set screws serving to hold and adjust the magnetic needles and other parts to the pivot-rods, are also in duplicate for the same purpose; Better and more reliable electric contact between the wires 2 and 3 has been obtained by using platinum against platinum, or platinum against gold.

Instead of directly coupling the detonator F, in the circuit with the sensitive needle 0, to be fired as soon as the contact between the wires 2 and 3 occur, the sensitive needle circuit includes a suitable device, such as an electro-magnet 32, Fig. 7, for causing the closing of another circuit directly including the detonator F, and thereby firing the mine.

In the preferred form of this part of the invention, another magnetic needle or rod m, is employed andis hereinafter termed the firing needle. This needle m, is mounted in the casing B, on a pivot-rod 33, the centers of which are carried by the shell 13 in a manner similar to that described with respect to the support of the pivot-rod 16.

The shell 13, also supports the electromagnet 32 arranged in proximity to one end of the firing needle m, and also a permanent magnet 36, arranged preferably in proximity to the other end of said needle, which latter is only sufiiciently strong to overcome the earths influence and normally to hold the firing needle against premature movement around its centers; while the electro-magnet 32 when energized will be sufliciently strong as to overcome the hold of the permanent magnet and cause the needle to turn on its centers a distance suflicient to close the electric circuit, including said detonator F, before referred to.

The firing needle m, and the magnets 32 and 36, are arranged in direct axial line with the axial lineof the sensitive magnetic needle 0, and are thus arranged so as to present the least disturbing influence to the position and deflecting movement of said needle 0.

The pivot-rod 32 with its wire 37, is in circuit through a battery G, with one wire of the detonator F, and a contact 38, in circuit with the other wire of the detonator. From which it results, that when the circuit including the electro-magnet is closed by the movement of the sensitive needle 0, the electro-magnet 32 being more powerful than the permanent magnet 36, repels or forces th end of the magnetic needle in proximity thereto away from it and attracting its other end to'a suflicient extent to cause its contact wire 37, to move against the contact 38, thereby closing the circuit including the battery G and the detonator F, and thus firing the mine.

The length of travel of the firing magnetic needle m, is so great and its movement comparatively deliberate in bringing the wire 37, and contact 38, into contact, that it requires, that the sensitive magnetic needle 0 shall remain or dwell in its deflected position positively 'holding'the wires 2 and 3 in contact for a distinct period of time, and hence a momentary contact of the wires 2 and 3 caused by the flickering of the sensitive needle, willnot bring about the firing of the mine. It is consequently requisite that the vessel to be destroyed be present, to causethe effective operation of the firing mechanism.

The electric circuit wires leading to the electro-magnet 32, and the wires leading from the firing magnetic needle m, may pass through a tube I, Fig. 6, extending from the cap of the casing B, through the body of the high explosive charge in the lower half of the mine to and through the partition H. The wires, of course, may be formedinto a cable and the tube be omitted. i The depth contact D, consists of a flexible diaphragm 40, closing an opening in the mine casing, with the head of a springpressed rod 41, resting against its inner side. When the pressure of the water against the diaphragm is strong enough to overcome the force exerted by the spring-pressed rod, that is to say, when the mine has reached a predetermined depth, the electric circuit from the sensitive needle through the battery IE, will be closed, and the mine he said to be armed. The access of water to the diaphragm may, however, be delayed for a short period of time, say from fifteen to thirty minutes, by the interposition of a plug 43, of a suitable material soluble in water, this soluble plug being held in an opening of a guard plate 42. During the time the plug is being dissolved the magnetic needles contained by the casing A will have had suflicient time to have become orientated.

To preserve the magnetic mechanism in the casing A as steady as possible, as well as to hold the same at all times in a horizontal position, the casing will be supported on gim bals of the usual form. In this instance, however, as seen in Fig. 3, the gimbal rings are increased to provide three points of suspension, the intermediate ring 45 providing bearings for the trunnions of the innermost ring 46, and also trunnions taking in bearings in the outer ring 47, which in turn has trunnions taking in hearings in the fixed frame 48, Fig. 6. The innermost gimbal ring 46, is preferably split into two halves to embrace the exterior of the shell 10, and to be clamped thereon in the proper place by screws as, passing through abutting ears on the ring.

lVhat is claimed is z.-

1. An orientating magnetic needle, a sensitive needle mounted therewith, and a third magnetic needle affected by the movement of the sensitive needle with respect to the orientating needle.

2. A pivoted rod formed of two parts united by an insulating portion, a magnetic needle directly carried by one part of the rod, and another magnetic needle supported by the other part of the rod.

3. A single pivoted rod supporting two magnetic needles, one movable irrespective of the'other.

4. A rod provided with a yoke and carrying a magnetic needle, another rod pivoted in the yoke of said first-named rod and also carrying a magnetic needle.

5. A magnetic needle, an axial rod asso ciated therewith being supported on centers, and another magnetic needle an axial rod associated therewith being supported at its opposite ends in bearings carried by the firstnamed rod.

6. A magnetic needle, an axial rod carrying the needle, and having at its opposite ends spring-pressed jewels, and centers in contact with said jewels.

7 A magnetic needle having its axis mounted upon bearings, a frame carrying said centers, a casing supporting said frame and gimbals providing a three point suspension for the casing.

8. A magnetic needle having its axis carried by bearings, a support therefor, gimbals carrying said support with one ofthe gimbal rings adjustably embracing said support.

9. A frame carrying bearings, a magnetic needle having an axial rod supported by said bearings, metallic jewels in contact with the bearings and in metallic contact with the axial rod and an electric circuit including the rod, its jewels and the bearings; 1

O. Two magnetic needles each adapted for independent movement, and a control magnetic needle for adjusting the normal position of one of said needles with respect to the other.

11. A magnetic needle mounted on a Vertical axis, another magnetic needle mounted on a horizontal axis and controlled by the deflection of the first-named needle.

12. A magnetic needle horizontally arranged, another magnetic needle vertically arranged in alinement with the axis of the first-named needle and means due to the deflection of thelatterneedle, causing the de fiection of said second needle.

In testimony whereof Ihave signed my name to this specification in the presence of two subscribing witnesses.

HUDSON MAXIM.

\Nitnesses:

LILIAN MAXIM, ALBERT H. G. ISENMAN. 

